class Data{
  String _name;
  int age;

  Data(this._name, this.age);
  Data.S(this.age);
  Data  operator + (Data data){
    var da = Data(_name, data.age + this.age);
   return da;
 }
 int su(F f){
  return f(1,2);
 }

  @override
  String toString() {
    return 'Data{name: $_name, age: $age}';
  }

}
typedef F( int x,inty);
